We stayed for 6 weeks in the apartment and we had a very good time.
The location is great if you want to stay a longer time. The MRT is within a few minutes. There is also a Gourmet Market with international goods and a Big C further down the street which has everything you might need.
Two 7 elevens are right outside, so is dry cleaning, a massage studio and a hair salon. Everything is of high quality.
The apartment it self is big enough for two people, with a good kitchen, comfortable bed (not too hard), a practical table and mostly well working Aircon.
The check-in process was smooth even though our taxi diver had a hard time finding the place (due to lack of our Thai and his English, every other taxi driver found us just fine) and Andy made sure we got the keys anyway. Everything was clean when we arrived.
The facilities are clean too. The Library had internet and plugs when we arrived but the last week of our stay that changed. Now it is not allowed to use the plug or you pay a 1'000 Bath fine. I don't know if they will change that again. The internet in the room is strong enough to work from home but it was nice to be able to switch it up from time to time.
Communication overall was super easy and it was easy to organise a housekeeper or getting tips where to go and what to do. (Chatuchack is about 30 Min a way from the apartment.)
Overall I would stay there again and recommend it if you don't want to be in the center of the hustle and bustle of the city.